That's the rule. You can't support a foreign power against your own unit. :-)

the rule is you can't DISLODGE your own unit.

For example

England: Swe-Den

Germany: F Bal S Swe-Den

that move would fail.

So the outcome was right, England can support a foreign power to disrupt his own attack? If the rule is you can't dislodge that would make some sense, but odd all the same.

That's the same difference right? I mean, you can issue the order. You can issue the unit in Pakistan to fly to Venezuela, it's just that that is a void order just like supporting someone else against your own unit...

It can be useful in creating a bounce with units, though a support hold would do the exact same thing

*order the unit

not really, redhouse

Let's say England has a fleet in the north sea and london. While Germany has a fleet in Skagerrak. France has a fleet in Belgium

England orders his fleet to Helgoland Bight. However, to make sure France gets the north sea then, England supports his move. However, if Helogland bounces, the north sea unit is not dislodged

however, in that case, if Germany also had a fleet in Denmark, that supported Ska-Nth, the North Sea would not be dislodged

It can also be used defensively.

For example, say that France is fighting a war against Germany and Italy. France has armies in Marseilles, Burgundy, and Ruhr. Germany has armies in Munich and Silesia. Italy has armies in Tyrolia and Piedmont, and a fleet in the Gulf of Lyon.

Italy wants to take Marseilles. To guarantee this, they need Burgundy's support to be cut. Thus, Germany orders Mun-Bur.

However, France could conceivably attack Munich. To defend against this, the German army in Silesia supports Tyrolia into Munich (as for why Silesia isn't covering Munich, suppose Austria is allied with France and might attack Tyrolia). If France attacks Munich with support, it is bounced out by the supported Italian army. However, since one can not support the dislodging of one's own units, the Italian army can not take Munich either. Munich is safe, unless the Germany army actually leaves it for good (i.e. the move to Burgundy succeeds).

Yeah, I revised it all, it's correct what you're saying. The order is not voided, the order is only voided if it would lead to the dislodging of your fleet. But, I'd like to comment; in Diplomacy you don't attack fleets and armies, you attack provinces, regardless of what's in it. :P

Yeah, so you could support an enemy unit to cause a standoff in one of your own territories, without having to worry that you will dislosge your own unit. (in most cases you could equally support yourself to hold) but there may be cases where this is actually useful.